Officials with the Bay County Sheriff’s Office say that 15-year-old Fredrick Matthew Lochridge of Fountain, Florida, shot and killed his 10-year-old sister, Izabella Heffernan, and then changed his sister’s clothes and moved her lifeless body to a large field about a quarter mile away from their home. Lochridge has since been charged with one open count of murder, according to a February 22 report from Fox News.

Izabella’s family reported her missing on Sunday, February 21 around 11:24 a.m. A frantic search for the child ensued which included helicopters, mounted police and K-9 units. Investigators found Isabella’s body in that field less than five hours later that same day, according to WJHG in Florida.

Sheriff McKeithen with the Bay County Sheriff’s Office said that his office had met the family about four or five years ago and the family then consisted of a man and woman and about six kids living in the same home but under deplorable conditions. McKeithen said that deputies volunteered their time to get the house fixed up “and tried to get it to where they could have some heat and water and things of that nature,” according to a quote from WJHG.

After finding Izabella’s remains, McKeithen said that the father, Lochridge, and the other kids from the home were taken to police headquarters for questioning. The mother is currently in prison after having been found guilty of accessory after the fact to second degree murder with a firearm.

While interviewing family members, deputies discovered that the father had already suspected that his son had something to do with the missing daughter. Deputies were informed that the father had even handcuffed Lochridge, but didn’t share any of that information when originally reporting Izabella as missing.

“I can tell you this, the 15-year-old boy was not your typical 15-year-old kid that you would see everyday on the street. He was a hard core kid. He lied. He was deceitful. He screamed. He cursed. He was like interviewing a 30-year-old murderer when we talked to him.” ~ Sheriff McKeithen via WJHG

Authorities still don’t have a motive for Izabella’s murder and are not ruling out a possible sexual assault. McKeithen is convinced though that it was Lochridge that shot and killed his 10-year-old sister. While being interviewed, the teen said that his sister had been shot before police formally released that information to him.

Lochridge eventually confessed to shooting his sister, but changed the circumstances surrounding the shooting at least three times. First he said he shot his sister while hunting and mistaking her for a deer, according to The Daily Mail. He later said he mistakenly shot his sister while trying to protect her from an attacker. Then he said he accidentally shot her while trying to teach her how to use a rifle.

Although charged with an open count of murder, officials are saying that “the State Attorney’s Office will file a second degree murder charge, the highest charge they can file at this time before the case sees a grand jury,” according to WJHG. McKeithen also said that it’s his hope that the 15-year-old Lochridge will be tried as an adult.